JP2015123252A - Light measurement device for living body, ultrasonic diagnostic device and light measurement method for living body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ultrasonic probe position guide in ultrasonic imaging utilizing light measurement for living body.SOLUTION: A light measurement device for living body includes a light irradiation unit, a plurality of light detection units, an image acquisition unit, and a calculation unit. The light irradiation unit is brought into contact with the surface of a living body and emits light to the surface substantially vertically. The plurality of light detection units are light detection units which are arranged at mutually different positions on the periphery of the light irradiation unit, at least one of which is inclined at a prescribed inclination angle with respect to the central axis of the light irradiation unit, and which detect the intensity of the light emitted from the light irradiation unit and diffused and reflected in the living body. The image acquisition unit acquires an image from detection means different from reflection light intensity distribution measurement of near infrared light with respect to the living body. The calculation unit calculates relative positions between the acquired image and light detection position from the signals of the plurality of light detection units and the image acquisition unit.

Description

  The embodiment of the present invention irradiates a living body with light containing a specific wavelength component, and detects the light diffusely reflected inside the living body by the irradiation at a plurality of positions on the living body surface, so that the position of the abnormal tissue or the like is not detected. The present invention relates to a living body light measuring device that accurately detects an invasion, a living body light measuring method, and an ultrasound diagnostic device that uses the living body inspection method.

  There are various techniques for measuring the inside of a living body non-invasively. Optical measurement, which is one of them, has the advantage that there is no problem of exposure and the compound to be measured can be selected by selecting the wavelength. A general biological light measurement device presses the light irradiation part against the surface of the living body skin and irradiates the inside of the living body through the skin, and measures the light transmitted or reflected again through the skin and emitted outside the living body. Various biological information is calculated based on the above. There is a difference in light absorption coefficient from normal tissue, which is the basis for determining the presence of abnormal tissue inside a living body by optical measurement. That is, since the absorption coefficient of the abnormal tissue is different inside the living body, a difference in the detected light amount according to the difference in absorption amount occurs. That is, by solving the detected light amount as an inverse problem, the absorption coefficient of the abnormal tissue can be obtained, and the property of the abnormal tissue can be determined from the obtained absorption coefficient. In addition, the measurement position and depth are analyzed using the measured light. This analysis method uses a method (spatial decomposition method) that adjusts the distance between the light irradiator (hereinafter abbreviated as the light source) and the detector, and a light source whose intensity changes with time, and the difference in the time that the light reaches There is a method for obtaining depth information from the time (time resolution method), and a method combining these. By these analysis methods, a biological light measurement device capable of acquiring a high-quality signal is realized. However, there is a problem in the low spatial resolution in the imaging of information by light in the living body. Furthermore, in order to obtain correct position information from the detection result of reflected light, it is necessary to calculate a large amount of data with a complicated algorithm, and it cannot be determined in real time.

  An example of an application that is highly feasible in biological light measurement is breast cancer testing (see Patent Document 1). However, as described above, since the optical measurement alone has problems in resolution and analysis time, a method for improving the inspection performance in combination with other modalities is desirable. Therefore, we have proposed a method of compensating for the low spatial resolution of light by using ultrasonic echo morphology information (see Patent Document 2). Although it is expected that the morphological feature in the living tissue and the component distribution of the morphological feature portion can be discriminated in a shorter time than before by this method, there is still room for improvement in the immediate judgment.

  By the way, breast cancer is one of the main causes of death in women. Breast cancer screening and early diagnosis have tremendous value in reducing mortality and reducing health care costs. Current methods include palpation of breast tissue and X-rays (mammography) to look for suspicious tissue deformations. If there is a suspicious part in the radiograph, an ultrasound image is taken and a surgical histology is performed. These series of tests take a considerable amount of time to reach a final conclusion. In addition, there is a problem in that the pre-menopausal young people have many mammary glands and it is difficult to obtain sensitivity in X-ray photography. Therefore, the screening by ultrasonic imaging is particularly significant for young people.

  In general, in ultrasonic imaging, an ultrasonic still image is collected by a certified operator, and judgment is made from morphological information on the image by a professional interpreter (in some cases). In view of the risk of oversight due to operator fatigue and reduced concentration, screening by a single operator is limited to a maximum of 50 people per day.

  In taking an ultrasonic image, the knowledge and experience of the operator is very important for collecting a still image capturing morphological features. Proficiency is also required for accurate and rapid screening. For example, the inspection time per subject is typically 5 to 10 minutes, but it may take longer depending on the skill of the operator. That is, in the current screening by ultrasonic imaging, the accuracy of image collection may vary depending on the skill level of the operator. Furthermore, since it is always necessary to pay attention to the image when collecting images, and it is left to the judgment of the operator alone, even a skilled operator has a great mental burden. There is also a method of collecting all image information with moving images, but in this case, the burden on the interpreter increases.

  In order to solve such problems in ultrasonic layer diagnosis, there is a method to reduce the burden on the engineer by guiding the measurement position of the ultrasonic probe in the surface direction based on the metabolic information of the living body obtained by living body light measurement. It has been proposed (see Patent Document 3). With such a method, it is possible to detect and discriminate abnormal sites in a short time and relatively easily in ultrasonic imaging.

JP 2005-331292 A JP 2007-020735 A JP 2009-079731 A JP 2009-168670 A

  However, there is still room for improvement in the conventional biological light measurement method, the biological light measurement apparatus using the method, and the ultrasonic probe position guidance for ultrasonic image capturing.

  The biological light measurement device according to the present embodiment includes a light irradiation unit, a plurality of light detection units, an image acquisition unit, and a calculation unit. The light irradiation unit is in contact with the surface of the living body and irradiates light substantially perpendicularly on the surface. The plurality of light detection units are arranged at different positions around the light irradiation unit, and at least one of the plurality of light detection units is inclined at a predetermined inclination angle with respect to the central axis of the light irradiation unit. The intensity of light emitted from the irradiation unit and diffusely reflected in the living body is detected. The image acquisition unit acquires an image from a detection means different from the reflected light intensity distribution measurement of near-infrared light with respect to the living body. The calculation unit calculates a relative position between the acquired image and the light detection position from the signals of the plurality of light detection units and the image acquisition unit.

FIG. 1 is a block configuration diagram of a biological light measurement device 4 including an optical probe 40 and an optical measurement processing unit 42. FIG. 2 shows a block configuration diagram of the ultrasonic diagnostic apparatus 1 in which the biological light measurement apparatus 4 according to the present embodiment is incorporated. FIG. 3 is a side view showing an example of the light guide unit 402 using a tapered structure. FIG. 4 is a diagram illustrating an arrangement example of the light irradiation unit 400, the plurality of light detection units 401, and the light guide unit 402 on the subject surface. FIG. 5 is a diagram of the probe P viewed from the subject contact surface side. FIG. 6 is a diagram for explaining the positional relationship between the light irradiation unit 400 and the light detection unit 401 using the detector tilt structure according to the light reception distance. FIG. 7 is a diagram showing an example of a cross-sectional view of an optical probe 40 having a detector tilt structure according to the light receiving distance. FIG. 8 is a cross-sectional view of the optical probe 40 shown in FIG. FIG. 9 is a diagram for explaining a simulation using the present optical probe 40. FIG. 10 is a diagram showing the distribution of the light intensity (relative intensity with respect to the value measured in the vertical direction with the inclination angle θ = 0) obtained for each inclination angle θ and rotation angle φ obtained by the simulation. FIG. 11 is a graph showing the components in the X-axis direction and the Y-axis direction of the light intensity obtained by the measurement using the optical probe 40 (FIGS. 7 and 8). FIGS. 12A and 12B are graphs showing the opening angle ψ obtained by the measurement using the optical probe 40 (FIGS. 7 and 8). FIG. 13 shows a flowchart of an ultrasonic probe guidance process using the living body light measurement apparatus 4.

  The living body light measurement device according to the present embodiment dramatically improves the amount of received light or the intensity of light received by the light detection unit by means of an inclined structure of the detector according to the light receiving distance. Such a light guide function according to the present embodiment can be applied to any biological light measuring device. In the following, for the sake of specific explanation, a biological light measurement device used in ultrasonic image diagnosis will be described as an example. In the following description, components having substantially the same functions and configurations are denoted by the same reference numerals, and redundant description will be provided only when necessary.

  FIG. 1 is a block configuration diagram of a biological light measurement device 4 including an optical probe 40 and an optical measurement processing unit 42. FIG. 2 shows a block configuration diagram of the ultrasonic diagnostic apparatus 1 in which the biological light measurement apparatus 4 according to the present embodiment is incorporated.

  The biological light measurement apparatus 4 includes an optical probe 40 and an optical measurement processing unit 42, and a support information generation unit 44 that generates support information for supporting the placement operation of the ultrasonic probe 12. In the present embodiment, as shown in FIG. 2, a description will be given of a biological light measurement device 4 incorporated in the ultrasonic diagnostic apparatus 1 (integrated with the ultrasonic diagnostic apparatus 1). However, without being limited to this example, the living body optical measurement device and the ultrasonic diagnostic device may have separate structures.

  The optical probe 40 includes at least one light irradiation unit 400, a plurality of light detection units 401, and a light guide unit 402 for improving light detection efficiency. The light irradiation unit 400 irradiates light (near infrared light) generated by the light source 420 substantially vertically toward the subject. The light detection unit 401 has a contact surface composed of, for example, an end of an optical fiber, and includes a plurality of detection elements that photoelectrically convert reflected light from within the subject that is input from the contact surface via the optical waveguide unit. . As the detection element, for example, a CCD, an APD, a photomultiplier tube, or the like can be employed in addition to a light receiving element such as a photodiode or a phototransistor. An optical matching layer may be provided on the contact surface of the light irradiation unit 400 with the subject.

  As shown in FIG. 3, the light guide unit 402 is provided between each light detection unit 401 and the subject surface, and the opening area on the subject surface side is larger than the opening area on the detection surface side of the light detection unit 401. And a conical structure (for example, a taper structure) that becomes larger. The light guide unit 402 guides (or condenses) light from the subject based on the irradiation light from the light irradiation unit 400, and dramatically improves the light detection efficiency in each light detection unit 401. The opening area of the light guide unit 402 depends on the opening angle ψ defined as shown in FIG. In particular, as will be described later, the biological light measurement device 4 according to the present embodiment detects the light guide unit 402 (and the light detection provided with the light guide unit 402 from the light incident position inside the subject by the light irradiation unit 400). The light guide 402 has different opening angles ψ depending on the distance (light receiving distance) to the portion 401). An optical fiber may be provided between the detection surface of the light detection unit 401 and the light guide unit 402. In such a case, the opening area on the light guide part side of the optical fiber is formed to be smaller than the opening area on the surface side of the subject of the light guide part.

  FIG. 4 is a diagram illustrating an arrangement example of the light irradiation unit 400, the plurality of light detection units 401, and the light guide unit 402 on the subject surface. In addition, although the abnormal tissue part is illustrated as a spherical absorber in the same figure, in the application of this embodiment, it is not restricted to the said example. The light emitted from the light irradiation unit 400 is repeatedly reflected (scattered) within the subject, and is emitted outside the subject again. Thus, since the light emitted outside the subject repeats scattering in the subject, the intensity is greatly attenuated compared to the incident light, and the direction is also dispersed. Therefore, for example, the intensity of light emitted from a certain point is greatly attenuated as compared with incident light.

  In order to evaluate the presence / absence and the nature of an abnormal tissue part in biological light measurement, it is necessary to compare the intensity of the emitted light with and without the abnormal tissue part. Furthermore, in the case of using for ultrasonic image diagnosis, in order to detect the approach state of the position to be ultrasonically picked up and teach the examiner and to guide the ultrasonic probe (and the optical probe 40), light The light intensity detected following the scanning of the probe 40 needs to have an SN ratio that can withstand the calculation. In the biological light measurement device according to the present embodiment, the SN ratio can be dramatically improved by the light guide unit 402 as will be described later.

  The optical measurement processing unit 42 includes a light source 420, an optical signal control unit 422, an optical analysis unit 424, and an arithmetic circuit 426. The light source 420 is light having a wavelength with small absorption in the living body (for example, light in the range of 600 nm to 1000 nm, which is a wavelength band called a living body window), and light having a specific wavelength that increases absorption at an abnormal site (for example, a living body window). A light emitting element such as a semiconductor laser, a light emitting diode, a solid-state laser, a gas laser, or the like that emits light in a wavelength range of 750 to 850 nm that is in a wavelength band range called “hemoglobin in blood”. The light generated in the light source 420 is supplied to the light irradiating unit 400 via an optical waveguide unit composed of an optical fiber or a thin film optical waveguide (or directly through propagation in space). The light source 420 may be integrated with the light irradiation unit 400.

  The optical signal control unit 422 controls the biological light measurement device 4 dynamically or statically. For example, the optical signal control unit 422 is irradiated with light from the light irradiation unit 400 at a predetermined timing, frequency, intensity, and intensity fluctuation period T under the control of the control processor 31 of the ultrasonic diagnostic apparatus 1. The light source 420 is controlled. Further, the optical signal control unit 422 controls the optical analysis unit 424 so that the optical analysis processing is executed at a predetermined timing.

  The light analysis unit 424 amplifies the analog signal input from the light detection unit 401 and converts it to a digital signal. Further, the light analysis unit 424 analyzes the change in the intensity of the detection light between the light detection units 401.

  The arithmetic circuit 426 is based on the change in the intensity of the detection light between the light detection units 401, the degree of adhesion between the ultrasonic probe 12 and the subject surface, and an abnormal part that shows a predetermined light absorption coefficient in the subject (for example, The depth of the object from the surface of the subject (the part that absorbs a specific wavelength more than the normal tissue), and the abnormal part with reference to a predetermined position (for example, the center of the light irradiation unit 400, the ultrasound transmitting / receiving surface 120, etc.) Calculate 3D position and distance. The calculation result in the arithmetic circuit 426 is sent to the support information generation unit 44.

  The support information generation unit 44 indicates the position, posture, orientation, etc. of the ultrasonic probe 12 based on the determination result and calculation result of the arithmetic circuit 42 in order to bring the transmission / reception surface of the ultrasonic probe 12 into close contact with the subject. Generate support information to guide. The generated support information is displayed in a predetermined form.

  Next, the ultrasonic diagnostic apparatus 1 will be described. As shown in FIG. 2, the ultrasonic diagnostic apparatus 1 includes an ultrasonic probe 12, an input device 13, a monitor 14, an ultrasonic transmission unit 21, an ultrasonic reception unit 22, a B-mode processing unit 23, a Doppler processing unit 24, A RAW data memory 25, a volume data generation unit 26, an image processing unit 28, a display processing unit 30, a control processor (CPU) 31, a storage unit 32, and an interface unit 33 are provided.

  The ultrasonic probe 12 constitutes a probe P together with the optical probe 40. The ultrasonic probe 12 is a device (probe) that transmits ultrasonic waves to a subject whose typical example is a living body, and receives reflected waves from the subject based on the transmitted ultrasonic waves. A plurality of piezoelectric vibrators, matching layers, backing materials, and the like. In the vicinity of the ultrasonic transmission / reception surface of the ultrasonic probe 12, for example, as illustrated in FIG. 5, the light irradiation unit 400 and the plurality of light detection units 401 of the biological light measurement device 4 are arranged in a predetermined form. The input device 13 is connected to the device body 11 and includes various switches, buttons, a trackball, a mouse, a keyboard, and the like for capturing various instructions for operating the ultrasonic diagnostic device 1 and the biological light measurement device. . The monitor 14 displays morphological information in the living body, blood flow information, and support information generated by the support information generation unit 44 in a predetermined form.

  The ultrasonic transmission unit 21 generates a trigger pulse for forming a transmission ultrasonic wave at a predetermined rate frequency fr Hz (cycle: 1 / fr second), gives a predetermined delay time, and then drives the probe 12. Apply a pulse. The ultrasonic receiving unit 22 amplifies the echo signal captured via the probe 12 for each channel, performs an A / D converter, and then performs an addition process by giving a necessary delay time. The B-mode processing unit 23 receives the echo signal from the receiving unit 22, performs logarithmic amplification, envelope detection processing, and the like, and generates data in which the signal intensity is expressed by brightness. The Doppler processing unit 24 extracts a blood flow signal from the echo signal received from the receiving unit 22 and generates blood flow data (blood flow information such as average velocity, dispersion, power, etc.).

  The RAW data memory 25 generates RAW data using a plurality of B mode data received from the B mode processing unit 23 and the Doppler processing unit 24. The volume data generation unit 26 generates B-mode volume data and blood flow volume data by executing RAW-voxel conversion including interpolation processing that takes into account spatial position information. The image processing unit 28 performs predetermined images such as volume rendering, multi-planar reconstruction display (MPR), maximum value projection display (MIP) on the volume data received from the volume data generation unit 26. Process. The display processing unit 30 executes various types such as dynamic range, brightness (brightness), contrast, γ curve correction, and RGB conversion on various image data generated and processed by the image processing unit 28. The control processor 31 has a function as an information processing apparatus (computer) and controls the operation of each component. The storage unit 32 stores a dedicated program, captured volume data, diagnostic information (patient ID, doctor's findings, etc.), diagnostic protocol, transmission / reception conditions, captured image, and other data groups.

  The interface unit 33 is an interface related to the input device 13, a network, and a new external storage device (not shown). It is also possible to connect an external biological light measurement device to the ultrasonic diagnostic apparatus main body 11 via the interface unit 33. Data such as ultrasonic images and analysis results obtained by the apparatus can be transferred by the interface unit 33 to another apparatus via a network.

(Inclined detector structure according to the light receiving distance)
Next, the inclination structure of the detector according to the light receiving distance of the biological light measurement device 4 will be described. In this structure, the angle (inclination angle θ) formed by the center axis of the light irradiation unit 400 (or the optical axis of light emitted from the light irradiation unit 400) and the center axis of each detector 401 is expressed as a light receiving distance R (light This is set individually for each detector 401 in accordance with the distance from the light incident position inside the subject by the irradiation unit 400 to each light detection unit 401.

  FIG. 6 is a diagram for explaining the positional relationship between the light irradiation unit 400 and the light detection unit 401 using the detector tilt structure according to the light reception distance. As shown in FIG. 6, in each light detection unit 401, the central axis of the detector 401 is inclined with respect to the central axis of the light irradiation unit 400 by an inclination angle θ according to the light receiving distance R from the light irradiation unit 400. Is provided. Here, the inclination angle θ takes a value of 0 degree or more and less than 90 degrees. For example, when the inclination angle θ = 0 degree, the central axis of the detector 401 is substantially equal to the central axis of the light irradiation unit 400. It is provided so that it may become parallel to. Although depending on the wavelength of light used for measurement, when light having a wavelength band (for example, 765 nm) called a biological window is used as incident light, the inclination angle θ = 0 of the detection unit 401 having a light receiving distance R of 5 mm or less. The inclination angle θ of the detection unit 401 having a light reception distance R greater than 5 mm is set to a value greater than 0 degree and less than 90 degrees, for example, and the inclination angle θ is individually set according to the light reception distance R. Provided.

  FIG. 7 is a diagram showing an example of a cross-sectional view of an optical probe 40 having a detector tilt structure according to the light receiving distance, which was experimentally manufactured by the inventors. FIG. 8 is a cross-sectional view of the optical probe 40 shown in FIG. As shown in FIGS. 7 and 8, the optical probe 40 has a plurality of guide holes 400h and a photodetector guide block 401g. As shown in FIG. 7, the plurality of guide holes 400h are arranged at predetermined intervals on the circumference of a concentric circle with the photodetector guide block 401g as the center. As shown in FIG. 8, the photodetector guide block 401g has a hemispherical (dome-shaped) housing provided with a plurality of photodetector guide holes 401h having different inclination angles θ, for example, in increments of 15 degrees. Yes. According to the present optical probe 40, the distance (that is, the light receiving distance) between the light incident part 400 and the photodetector guide block 401g is adjusted by changing the guide hole 400h into which the incident fiber of the light incident part 400 is inserted. In addition, by changing the guide hole 401h into which the receiving optical fiber of the light detector 401 is inserted, the angle formed by the central axis of the light incident part 400 and the central axis of the light detector 401 (that is, the inclination angle θ) is adjusted. can do.

  The present inventors performed the following simulation using the optical probe 40 in order to obtain a suitable inclination angle θ according to the light receiving distance. That is, as shown in FIG. 9, the light receiving distance R = 10 mm, and the guide hole 401h into which the receiving optical fiber is inserted is changed to change the inclination angle θ from −60 degrees to +60 degrees in steps of 15 degrees. The rotation angle φ formed by the extension line of the straight line connecting the center of 401 and the center of the light irradiation unit 400 (X axis in FIG. 9) and the straight line P projecting the central axis of the light detector 401 onto the living body surface is also incremented by 15 degrees. The experiment was conducted to measure the light intensity detected by the detector 401 by changing from −60 degrees to +60 degrees. In addition, a Monte Carlo simulation corresponding to this measurement was performed. In the simulation, the inclination angle θ was changed from −90 degrees to +90 degrees. Incident light (765 nm) was incident vertically on the sample surface, and the reflected light intensity was measured at a position 10 mm away from the incident position. In the sample, a scattering agent and a pigment were dispersed in a resin and solidified, and the scattering coefficient and the absorption coefficient were matched with those of a living body.

  FIG. 10 is a diagram showing a distribution of light intensity (relative intensity with respect to a value measured in the vertical direction with the inclination angle θ = 0) obtained for each inclination angle θ and rotation angle φ obtained by the simulation. FIG. 11 is a graph showing the components in the X-axis direction and the Y-axis direction of the light intensity obtained by the above experiment. From FIG. 11, it can be found that the detected light is the maximum when the inclination angle θ is 15 degrees and is significantly larger than the intensity of the detection light when the inclination angle θ is 0 degrees. In order to correctly determine the angle range showing the effect of increasing the signal as compared with the tilt angle of 0 degree, from FIG. 10, light having a sufficiently large intensity with respect to the intensity of the detected light in the case of the tilt angle θ = 0 degree is obtained. The range of the inclination angle θ that can be detected is, for example, in the range of 10 degrees to 40 degrees, and it can be confirmed that the increase effect is particularly large in the range of 15 degrees to 35 degrees.

  In addition, the biological light measurement device 4 according to the present embodiment includes the light guide unit 402 having different opening angles ψ according to the light receiving distance. In order to obtain a suitable opening angle ψ of the light guide unit 402 for each light receiving distance, the inventors of the present invention have an inclination angle θ and a detected light intensity when the light receiving distance is 30 mm and when the light receiving distance is 34 mm, respectively. The measurement using the optical probe 40 shown in FIG. 6 was performed for each of the opening angles ψ = 10 degrees, 20 degrees, and 30 degrees of the light guide unit 402.

  FIG. 12A and FIG. 12B are graphs showing the graphs obtained by the above measurement. As can be seen from FIGS. 12 (a) and 12 (b), the intensity of the detected light is maximized when the opening angle ψ = 20 degrees in both cases where the light receiving distance is 30 mm and 34 mm. In addition, such an effect of increasing the light guide efficiency by the light guide unit 402 was confirmed when the opening angle ψ was in the range of 10 degrees to 30 degrees.

  In the present embodiment, a configuration in which the light guide unit 402 is provided in all the light detection units 401 is illustrated. However, without being limited to the example, for example, a predetermined range in which the light guide effect by the light guide unit 402 is particularly noticeable (for example, a distance between the light irradiation unit of the plurality of light detection units is 5 mm or more) A light guide unit 402 may be provided for the light detection unit 401 in FIG.

  Next, an ultrasonic probe guidance process using the biological light measurement device 4 according to the present embodiment will be described. FIG. 13 shows a flowchart of an ultrasonic probe guidance process using the living body light measurement apparatus 4. As shown in the figure, when light is irradiated from the light irradiation unit 400 substantially perpendicularly on the surface of the living body (step S1), the light diffusely reflected in the living body has a plurality of different opening angles ψ depending on the light receiving distance. Are detected by a plurality of photodetectors 401 having individual inclination angles θ while being guided by the light guide unit 402 (step S2). The optical analysis unit 424 amplifies the detected optical signal (analog signal), converts it to a digital signal, and analyzes the change in the intensity of the detected light between the optical detection units 401 (step S3). The arithmetic circuit 426 is based on the change in the intensity of the detection light between the light detection units 401, the degree of adhesion between the ultrasonic probe 12 and the subject surface, and a subject at an abnormal site that shows a predetermined light absorption coefficient in the subject. The depth from the surface and the position and distance of the abnormal part with the predetermined position as a reference are calculated (step S4).

  The support information generation unit 44 indicates the position, posture, orientation, etc. of the ultrasonic probe 12 based on the determination result and calculation result of the arithmetic circuit 42 in order to bring the transmission / reception surface of the ultrasonic probe 12 into close contact with the subject. Support information to be guided is generated (step S5). The generated support information is displayed on the monitor 14 in a predetermined form (step S6).

(Modification)
In the embodiment, the inclination angle θ of each photodetector 401 and the opening angle ψ of each light guide unit 402 are fixed according to the light receiving distance. However, the present invention is not limited to this example. For example, a moving mechanism that can freely adjust the inclination angle θ and the opening angle ψ may be provided as necessary.

  According to the biological light measuring apparatus described above, the inclination angle θ, which is an angle formed by the central axis of the light irradiation unit and the central axis of each detector, is individually set for each detector 401 according to the light receiving distance R. To do. Further, the opening angle ψ of the light guide having a tapered structure provided between the detector and the subject surface is also set individually for each detector 401 according to the light receiving distance R. According to this configuration, since the emitted light from the living body is not completely diffused light in the light scattering specification of the living body, the light that is repeatedly scattered inside the subject and emitted outside the subject is higher than before. It can be collected with efficiency. Therefore, biological light measurement can be executed at a higher S / N ratio than before, and the presence of a suspicious tissue inside the subject can be determined and presented. When the position of the ultrasonic probe is guided using the biological optical measurement device according to the present embodiment, the approach state of the suspicious tissue can be detected and presented more accurately, and an ultrasonic image based on the proficiency level of the operator It is possible to reduce the variation in the quality of diagnosis.

  In addition, as a conventional biological light detection device, for example, there is one disclosed in International Publication No. WO2006 / 132218. This living body light detection device has a function of making the opening area of the waveguide different between the living body side and the detector side in order to receive all the light from the subject and making the living body side larger. The light naturally generated from within the subject is detected without irradiating the light. On the other hand, the biological light measurement apparatus 4 according to the present embodiment has a light receiving distance (a distance between an incident position of light irradiated inside the subject and an output position of light propagating through the subject and emitted outside the body). This is based on a new experimental fact that the effect of this light guide is different and the effective diameter is also different. Therefore, the biological light detection device 4 according to the present embodiment achieves a remarkable technical effect that cannot be realized by a conventional biological light detection device.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic diagnostic apparatus, 11 ... Apparatus main body, 12 ... Ultrasonic probe, 13 ... Input device, 14 ... Monitor, 21 ... Ultrasonic transmission unit, 22 ... Ultrasonic reception unit, 23 ... B mode processing unit, 24 ... Doppler processing unit, 25 ... RAW data memory, 26 ... volume data generation unit, 28 ... image processing unit, 30 ... display processing unit, 31 ... control processor (CPU), 32 ... storage unit, 33 ... interface unit, 40 ... light Probe ... 42 Optical measurement processing unit 44 ... Support information generation unit 400 ... Light irradiation unit 400 ... Light detection unit 402 ... Light guide unit 420 ... Light source 420, 422 ... Optical signal control unit 424 ... Optical analysis unit 426: arithmetic circuit, P: probe

Claims (9)

A light irradiation unit that is in contact with the surface of the living body and irradiates light substantially perpendicularly on the surface;
A plurality of light detection units arranged at different positions around the light irradiation unit, at least one of which is inclined at a predetermined inclination angle with respect to the central axis of the light irradiation unit, each irradiated from the light irradiation unit A plurality of light detection units for detecting the intensity of light diffusely reflected in the living body;
An image acquisition unit for acquiring an image from a detection means different from the reflected light intensity distribution measurement of the near-infrared light for the living body;
A calculation unit for calculating a relative position between the acquired image and the position of the light detection from signals of the plurality of light detection units and the image acquisition unit;
A biological light measurement device comprising:   The biological light measurement according to claim 1, wherein at least one light detection unit inclined with respect to a central axis of the light irradiation unit is a light detection unit having a distance of 5 mm or more from the light irradiation unit. apparatus.   The biological light measurement apparatus according to claim 1 or 2, wherein the inclination angle is in a range of 10 degrees to 40 degrees. The light is near infrared light;
A plurality of light guides provided in at least one of the plurality of light detection units, interposed between the light detection surface and the surface of the living body, and having a contact area on the living body surface side larger than an opening area on the light detector side Further comprising a body,
The biological light measurement device according to claim 1, wherein   The living body light measurement device according to claim 4, wherein a contact area on the living body surface side of the plurality of light guides increases as a distance from the light irradiation unit increases.   The biological light measurement device according to claim 4, wherein the plurality of light guides are optically connected to the light detection unit via an optical fiber and have an opening larger than the opening of the optical fiber.   The biological light measurement device according to any one of claims 4 to 6, wherein the plurality of light guides have a conical shape with an opening angle of 20 degrees or more and 60 degrees or less. An ultrasonic probe that transmits ultrasonic waves from the ultrasonic transmission / reception surface to the subject and receives ultrasonic waves reflected in the subject via the ultrasonic transmission / reception surface;
A plurality of light detection units that are arranged at different positions around the ultrasonic transmission / reception surface with the central axis in the longitudinal direction of the ultrasonic transmission / reception surface as a symmetry axis, and detect the intensity of the light reflected in the subject; A plurality of light detection units arranged at different positions around the light irradiation unit, at least one of which is inclined at a predetermined inclination angle with respect to the central axis of the light irradiation unit, each irradiated from the light irradiation unit A plurality of light detection units for detecting the intensity of light diffusely reflected in the living body, and an optical probe,
An image generation unit that generates an ultrasonic image using ultrasonic waves received by the ultrasonic probe;
A calculation unit for calculating the position and size of an abnormal site showing a predetermined light absorption coefficient in the subject based on the intensity of light detected in each of the light detection units;
A display unit for displaying the ultrasonic image showing the position and size of the abnormal site;
An ultrasonic diagnostic apparatus comprising: Irradiate light approximately perpendicularly to the surface from the light irradiation unit that is in contact with the surface of the living body,
The light irradiation unit is irradiated from the light irradiation unit using a plurality of light detection units which are arranged at different positions around the light irradiation unit and at least one of which is inclined at a predetermined inclination angle with respect to the central axis of the light irradiation unit. Detecting the intensity of light diffusely reflected in the living body,
Obtain an image from a detection means different from the reflected light intensity distribution measurement of the near-infrared light for the living body,
Calculating a relative position between the acquired image and the position of the light detection from signals of the plurality of photodetectors and the image acquirer;
A biological light measurement method comprising: